Javascript 使用选定选项显示图像

我正在做一个网站的问题和答案，其中几个选择题将显示，用户将不得不选择单选按钮来回答问题。提交后，会显示正确答案和错误答案，用户可以选择查看正确答案。 在本页中，为了查看正确答案，我想做的是为正确选项显示勾号图像，为所有其他错误选项显示十字图像。但我在写逻辑时遇到了问题。 这就是我到现在为止所做的

此页面用于选择要显示的图像

<?

        session_start() ; 
        $wrong =  array() ;
        if( !empty($_SESSION['wrongAnswer'] ) )  {
            $wrong = $_SESSION['wrongAnswer'] ;//wrongAnswer array has  
                                               //ids of wrongly answered 
                                               //questions         

            session_destroy() ;
        }

        if( !empty($_POST['wrongAnswer'] ) )  {
            $wrong = $_POST['wrongAnswer'] ; 
        }

        $i = 0 ;
        $quesID = ""; 
        $question = "" ;
        require_once "connection.php";  
        foreach ($wrong as $n) {     

       <?  $query = "SELECT * FROM answers WHERE question_id = '$n' " ;
            if($result = $mysqli->query( $query ) )  {
               if( $row = $result->fetch_object() ){
                    $answer = $row->answer ;

                 // $count++;
                }
                else 
                    echo "Couldn't tally answer " . $mysqli->error ;

            }

            else
                echo "Error executing query" . $mysqli->error ;


                                  //<----- THIS IS WHERE THE WRONGLY ANSWERED QUESTIONS WILL BE DISPLAYED WITH IMAGES AS MENTIONED BEFORE ------>//

                $query = "SELECT * FROM questions WHERE questionid='$n' " ;
                 $i ++ ;
                 if( $result = $mysqli->query( $query ) )  {  
                     $count= $result->num_rows ;
                      echo '<form name = "checkans.php" action = "checkans.php" method = "POST" >' ;

                     $row = $result->fetch_object()  ; 
                              //  $i++ ;
                               $quesID = $row->questionid ;
                               $question = $row->question ;

                                $quesID = $row->questionid ;
                                $query2 = "SELECT option1,option2,option3,option4 FROM options WHERE questionid='$quesID'" ;
                                if($result2 = $mysqli->query($query2) )  {
                                    if($row2 = $result2->fetch_object() )  {
                                        $option1 = $row2->option1 ;
                                        $option2 = $row2->option2 ;
                                        $option3 = $row2->option3 ;
                                        $option4 = $row2->option4 ;

                                       ?>
                      <table border="0" cellpadding="0" cellspacing="0">
                <?  echo "<div  id = $row->questionid name = boxs>" ; ?>
                <th> <h2> <? echo $i .")" ; ?>  </h2>  </th> 
                <th> <h2> <?echo $row->question ;?> </h2> </th> 

          <tr>  <input type="hidden" name="quesID[]" id="<? echo $quesID ; ?>" value="<? echo $quesID ; ?>">
            <div id = "options">
            <td>
            <span id = "1"> 
            <img id = "image" height="50px" width="50px">
            </td>
          <td>  
        <label>
          <? echo $option1 ;?>
        </label>
            </td>
        </span>

        <td>
        <span id = "2">
            <img id = "image" height="50px" width="50px">

          </td>
          <td>
        <label>
          <? echo $option2 ;?>
        </label>
        </td>
        </span>

        <td>
        <span id = "3">
            <img id = "image" height="50px" width="50px">

          </td>
          <td>
        <label>
          <? echo $option3 ;?>
        </label>
        </td>
          </span>

          <td>
          <span id = "4">
            <img id = "image" height="50px" width="50px">



          </td>

          <td>
        <label>
          <? echo $option4 ;?>
        </label>
        </td>
            </div>

        </span>
        </div>

              </tr>

          </table> 
            </section>
        <?          
                                    }
                                    else 
                                        echo "No options available for this question" ;
                                }


         }
         ?>
         <script type="text/javascript">
                var i = 0
                for(i=1; i <= 4; i++)  {
                    var y = document.getElementById(i);
                    //alert(y.childNodes)
                    var x = document.getElementById("image");
                    if( y.id ==  (<?echo $answer ; ?>) )  {
                        x.src = "correct.png" ;
                    }
                    else
                        x.src = "wrong.jpg" ;


                }


        }

    </script>
    <?
       }
    ?>